Nonwoven continuous filament product and method of preparation



April 7, 1970 R. H. BALCH ET AL 3,505,155

NONWOVEN CONTINUOUS FILAMENT PRODUCT AND METHOD OF PREPARATION FiledAug. 7, 1967 3 Sheets-Sheet 1 FIG 3 INVENTOR RALPH H. BALCH GEORGE A.WATSON HERBERT W COATES April 7, 1970 H. BALCH ET AL 3,505,155

NONWOVEN CONTINUOUS FILAMENT PRODUCT AND METHOD OF PREPARATION FiledAug. 7, 1967 3 Sheets-Sheet 2 H G 8 INVENTOR RALPH HBALCH GEORGE A.WATSON HERBERT W COATES A'ITO NEY April 7, 1970 R. H. BALCH ET AL3,505,155

NONWOVEN CONTINUOUS FILAMENT PRODUCT AND METHOD OF PREPARATION FiledAug. 7, 1967 3 Sheets-Sheet 3 FIG 9 FIG IO FIG l2 INVENTOR RALPH H BALCHGEORGE A. WATSON HERBERT W. COATES Ww QZM ATIOR EY United Patent3,505,155 Patented Apr. 7, 1970 3,505,155 NONWOVEN CONTINUOUS FILAMENTPRODUCT AND METHOD OF PREPARATION Ralph H. Balch, Charlotte, George A.Watson, Davidson, and Herbert W. Coates, Charlotte, N.C., assignors toCelanese Corporation, New York, N.Y., a corporation of DelawareContinuation-impart of applications Ser. No. 325,254, Nov. 21, 1963, andSer. No. 501,105, Oct. 22, 1965. This application Aug. 7, 1967, Ser. No.658,781

Int. Cl. B32b 5/12, 7/08, 31/08 US. Cl. 161-57 29 Claims ABSTRACT OF THEDISCLOSURE Background of the invention This is a continuation-in-part ofSer. No. 325,254 filed Nov. 21, 1963 and Ser. No. 501,105 filed Oct. 22,1965, both now abandoned.

This invention relates to continuous filament nonwoven products and moreparticularly to products produced by dimensionally stabilizing a spreadweb of continuous filament deregistered crimped tow.

Nonwoven fibrous products are well known in the art. Normally, suchproducts are made from staple fibers but more recently, methods havebeen devised for producing various products from continuous filaments.As is well known, staple fiber nonwovens by their vary nature, are notpossessed of any considerable inherent tensile strength in any directionand thus are ordinarily easily distorted and even destroyed unlessspecially reinforced. Even when reinforced, it has been found thatstaple fiber nonwovens do not have the desired degree of stability anddurability, because they not only tend to lose fibers through migration,but they are also inadequate in the ability to retain bulk,compressibility, resilency and the like.

To avoid some of these drawbacks and disadvantages, it has previouslybeen proposed to utilize continuous filaments. Various methods have beendevised to produce nonwoven sheet materials composed of continuousfilaments. While such processes have various advantages for particularuses, certain disadvantages also accompany many of these processes.Particularly, most of such continuous filament processes are limited toproduction by the filament manufacture and the resulting product cannotbe readily changed subsequently by the manufacture of the finishedproduct if somewhat different physical characteristics of the fabric orsheet material are desired. Also, many of these processes rely upon meltadhesion of the fibers to bond each other while still in a relativelyplastic condition. This type of bonding greatly limits certain bulkcharacteristics often desired in the end product.

- It is an object of the present invention to provide a dimensionallystabilized, nonwoven, deregistered, crimped, continuous filament productparticularly suitable for a wide variety of end uses, particularly bulkyproducts of an insulating and/or cushioning character. It is anotherobject of the present invention to provide a method for producing suchproducts. These and other objects will become apparent to those skilledin the art from a description of the invention which follows:

Summary of the invention In accordance with the invention a nonwovencontinuous filament product is produced comprising deregistering a towof crimped continuous filament, spreading the deregistered tow toproduce a web and subsequently dimensionally stabilizing the web toproduce the nonwoven continuous filament product. Dimensional stabilityis preferably achieved by bonding and/ or stitching and/ or laminatingthe spread web to a sheet material.

The present invention is particularly suitable for the production ofinsulating material and cushioning material as well as fibrous sheetmaterial suitable for clothing, synthetic paper, pillows, carpets,carpet underlay pads, mattress pads, quilts, and the like. Whenattaching a spread web to a dimensionally stable sheet such as a wovenfabric such as by stitching, unexpectedly full and bulky products areobtained by securing the fibrous web to the sheet material while holdingthe fibrous web under tension. The resiliency and bulkiness of thefibrous web creates a putty, full product when the tension is released,

due to the tendency of the spread Web to return to its originallongitudinal length. Thus, extremely bulky insulating products such asinsulating clothing, mattress pads, sleeping bags, pillows :and thelike, cushioning and insulating materials are produced With greatlyimproved bulky properties. Further, these characteristics arepermanently retained in the end product even after extensive usage andwashings.

Brief description of the drawings The invention will be more fullydescribed by reference to the drawings in which:

FIG. 1 is a schematic illustrating a method of deregistering acontinuous filament tow and subsequently spreading the tow into a web;

FIGS. 2 and 3 are schematic illustrations of methods and apparatuses forapplying a bonding agent to the spread tow or web;

FIG. 4 is a schematic illustration of a method for producing a pleatedor corrugated web from spread tow to which a bonding agent has beenapplied;

FIG. 5 is a plan view of a section spread tow to which a bonding agenthas been applied in the form of discrete dots or small areas;

FIG. 6 is a schematic illustrating a method which may be employed tofolding and/or linearly lay or cross lay a spread tow to produce a webof increased thickness;

FIG. 7 is a schematic illustrating a method which may be employed tolaminate a web of spread tow onto one or more additional webs or sheetmaterial;

FIG. 8 is a schematic illustrating a method for dimensionallystabilizing a web by stitching the web or plurality of webs tothemselves or stitching the web to a sheet material;

FIG. 9 is a view along line 9-9 of FIG. 8, further illustrating the webstitching method and showing a pretensioning device through which thespread tow is passed prior to the stitching operation;

FIG. 10 is a schematic illustrating another method for laminating one ormore webs of spread tow' to each other or to a sheet material;

FIG. 11 is a schematic illustrating another method for making a bulkymaterial by attaching a pleated or corrugated web between two sheetmaterials; and

FIG. 12 is an enlarged partial, sectional view of a composite fabricbody produced by the method of FIG. 11.

3 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring moreparticularly to FIG. 1, a band of crimped continuous filament tow isdrawn from a bale 12 through a banding jet 13. Banding jet 13preconditions the tow for further processing by removing snags, falsetwists and the like and straightens and flattens the tow so that it maybe more readily processed. From banding jet 13, the tow is passed aroundstationary tensioning bars 17 and 18 prior to passing into the towopening zone.

The tow is conveniently opened or deregistered to prepare it for one ormore spreading stages, by subjecting it, while moving in a predeterminedpath, to a differential gripping action between the plurality of pointsspaced from one another both longitudinally and transversely in the pathso that certain laterally spaced sections of the tow are positivelygripped relative to other laterally spaced sections of the tow.Alternating with the grip sections are sections where the tow is notgripped at all or it is gripped at different relative points. In thismanner there is produced a relative shifting of the adjacent filamentslongitudinally along the tow whereby the crimps are moved out ofregistry with one another. The shifting action is a function of thedifferential positive gripping of the tow. Preferably, although notnecessarily, the differential gripping action is such that a relativelateral displacement between adjacent filaments of the tow is alsoeffected, so that the combination of two transverse filament movementsbrings about the complete opening of the tow.

Several methods for effecting the differential gripping action are knownin the art as well as several different apparatuses for effectingdifferential gripping, which apparatus deregister the tow with varyingdegrees of success. A preferred apparatus and method is disclosed byDunlap et al., in US. Letters Patent 3,156,016.

Typically, the differential gripping is achieved by using at least onepair of rollers, one of which is smooth surfaced and the other of whichis patterned over its entire periphery. The most preferred apparatuscomprises a plurality of such pair of rollers arranged in tandem whereinone of each pair of rollers comprises a smooth surfaced roll coated witha resilient material such as rubber, and the other roller hasalternating lands and grooves. Preferably, the lands and grooves formhelical threads of about 8 to 20 threads per inch.

It will be apparent that the opening of the tow for the purposes of thepresent invention may be effected by means differing from the threadedroll type of apparatus disclosed in the aforesaid Dunlap et al. patent,although this tow opening and crimp deregistering apparatus is preferreddue to its high efficiency and its uniformity of operation. For example,the grooves on the roll need not be helical but could have otherconfigurations such as circular rings. If desired, the grooves may bediscontinuous i.e. take the form of intermittent depressions in thesurface of the roll, and may, for example, impart to the roll surface acheckerboard or other pattern of alternately raised and depressed areas.Both rolls of any one set could be grooved, if desired, although bestresults are achieved when but one roll is so grooved. The path of thetow in moving between the nips of successive roll sets is horizontal inthe Dunlap et al. disclosure but can be made vertical if desired.

Thus, the tow is passed through the nip of a pair of rollers 19 and 21prior to being passed through a second pair of rolls 22 and 23. In themost preferred embodiment, rolls 19 and 23 are patterned rolls such asthreaded steel rolls and rolls 21 and 22 are resilient surfaced rolls.

Each pair of rolls is individually driven at a predetermined controlledspeed. Generally, only one roll of each pair is positively driven whilethe other is in yieldable compressive contact with the driven roll androtates due to the passing of the tow between the rollers. Thedifferential gripping and deregistering action is produced by driving 4the second pair of rollers at a faster rate of speed than the firstpair. Thus, the second pair of rollers is typically driven at a rate ofabout 1.1 to about 8 times and more preferably, at a rate of about 1.2to about 3 times that of the first pair.

On leaving the deregistration zone, the crimp in the tow is out ofregistry with adjacent filaments.

After deregistering the tow, the tow is subjected to one or morespreading stages. Various spreading means can be used to spread thederegistered tow into a uniform web. Such means include mechanicalspreading bars, diverging belts, air jets and the like. The mostpreferred means is an air jet. Using such spreading means, the tow canbe spread into a web of relatively great width ranging up to about 80inches or more depending on the denier and number of filaments of thetow being spread. Because the most preferred means of spreading is byuse of an air jet, the invention will be described more particularlywith reference to air spreading although it is to be understood thatother types of spreaders can be used.

The tow passing from the deregistration zone is thus passed through afirst spreader 24. The tow is pulled through the spreader 24 by theaction of driven rollers 36 and 37 about which tow 10 is S wrapped. Inpassing through spreader 24, the tow is spread about 2 to 4 times thewidth of the tow exiting from the deregistration zone. As is oftenpreferred in the present invention, the tow is preferably again spreadin a second spreader 38 wherein the spread band is again spread to 2 to4 times the width of the web drawn through rollers 36 and 37. Again theWeb is drawn through spreader 38 by means of another set of drivenrollers 39 and 41. Thus, the spreading action preferably spreads the towinto a web at least twice the original width of the tow and morepreferably at 2 to about 10 times the original tow width to produce alightweight web of less than about 1 ounce per square yard. Morepreferably, webs in the weight range of about 0.005 to 0.5 ounce persquare yard and most preferably of about 0.01 to about 0.25 ounce persquare yard are readily produced.

From rolls 39 and 41, the tow falls in a freely hanging shallow catenary42 onto a horizontal moving surface of a wide endless belt 43. Idlerroll 44 mounted on lever arm 46 pivoted at 47, extends across the fullwidth of the web on belt 43. The idler roll serves to bring the tow webinto firm contact with belt 43, to define the shape and position ofcatenary 42 and also to keep any loose ends in the catenary portion frombeing drawn around roller 41.

The spread web is then in condition to be dimensionally stabilized toform a more useful end product. As will be readily recognized, thespread web has substantial stability in the longitudinal direction alongthe direction of the filaments but the stability across the widthdirection is extremely low. Thus, applying a tensile forcelongitudinally along the filament length will result in a substantialstrength, depending on the fiber used, with substantial recovery to theoriginal length. However, by applying a tensile force across the widthof the web, comparatively little resistance will be noted and arelatively low recovery will result. Thus, the web can be readily splitin this manner thus losing its integrity as a web.

The present invention is useful with all continuous filament materialswhich have been crimped prior to deregistration. The process isparticularly useful with filaments of polyethylene terephthalatepolyester and cellulose acetate of the usual acetyl content of about 54to 55 percent calculated as acetic acid. However, the invention is alsoequally applicable to other tows such as those made of other polyesterssuch as polyesters of 70/30 isophthalic and terepthalic acids and otherglycols such as dimethylolcyclohexane; linear super polyamides such asnylon 6 and nylon 66; polyacrylonitrile and copolymers of acrylonitrile;olefinic polymers and copolymers such as isotactic polypropylene; otherorganic derivatives of cellulose such as esters and/ or ethers ofcellulose, for example cellulose propanate and cellulose acetatepropanate and the like; highly esterified cellulose containing less than0.29 free hydroxyl groups per anhydroglucose units such as cellulosetriacetate, rayon and the like.

The number of filaments in the starting tow can vary within wide limitsand may range up to as high as about one million with a denier perfilament as high as about 25, that is, in the range of about 0.5 toabout 25 and more preferably in the range of 1 to 20 denier perfilament. The number of crimps per inch of tow may range up to as highas about 80, but for most end products a crimp of about 3 to 50 crimpsper inch, preferably about 3 to 20 crimps per inch of starting tow arefound to be exceptionally satisfactory.

Referring more specifically to FIGS. 2 and 3, the spread web can beunified or dimensionally stabilized without recourse to auxiliary sheetmaterials. Accordingly, in one aspect of the invention, the spread webis passed through a fibrous bonding applicator device 48 wherein thebonding agent is applied to the spread web. Various means for applyingthe bonding agent to the web can be utilized including sprayapplications, dip coating, roller coating and the like which may bedesigned to apply the bonding agent to either one or both surfaces ofthe web. Various bonding agents can be used as are well known in theart. The bonding agent may be a plasticiser or solvent for thethermoplastic material of which the filaments are composed, or asuitable adhesive composition which is compatible with the thermoplastimaterial. The particular bonding agent used can be chosen to givecertain characteristics to the end product. For instance, a flexiblebonding agent is used when the end product is to be used for softcushioning material and a rigid type bonding agent is used when suchcharacteristics are desired. For cellulose acetate filaments, forexample, a plasticiser such as triethylcitrate, dimethoxyethylphthalate,methylphthalyl, ethylglycolate and glycerol triacetate (triacetin) or asolvent such as acetone may be employed. For polyester filaments varioussubstances such as chloral hydrate and certain synthetic polymeremulsions have been found to be particularly suitable. Emulsion polymerssuch as polyurethane latexes, melamine formaldehyde resins, but a dieneresin and the like are examples of other typical bonding agents.

As will be readily recognized, in order to enable maximum possibleproduction rates, the bonding agent is preferably of a quick setting orquick drying type. Thus, the web upon leaving applicator 48 may bepassed through a heater dryer apparatus 49 or the like or it may bepassed over an open air framework 50, which is particularly suitable ifthe bonding agent is of the air drying type, prior to being fed to atake up means 51.

The total amount of bonding agent applied per unit area web can varywidely from about 2 to about 200 percent of the dry base weight of theweb and more preferably within the range of about 5 to 100 percent whichhas been found to be highly preferred for most end uses. It will berecognized that the bonding can take place either with the initiallightweight web or after layering the lightweight web so as to comprisea web having a plurality of lightweight webs laying one on top of theother. Alternatively, the lightweight web can be cross lapped ratherthan layered prior to the bonding operation.

The base weight of the web or spread tow will depend principally on theinitial characteristics of the tow such as the total denier and denierper filament of the starting tow and also on the amount of spreading toform the web. While the spread web is preferably of a weight of lessthan about 1 ounce per square yard, the web being impregnated may becrosslapped or layered as hereinbefore noted so as to increase theweight of the web to 8, 12,

16 or more ounces per square yard as may be desired for the particularend use.

The bonded filamentary material is advantageously employed as industrialair and liquid filters, fabrics, both with and without calendering, andthe like products, of which substantial tensile strengths and theability to retain the original shape are important characteristics.Alternatively, the bonded web can be further processed as hereinafterdescribed.

When a bulkier base material is desired, one manner of treating thefilamentary web is in accordance with FIG. 4. In accordance with thisarrangement, the spread web 10 is fed by feed rollers or the like into astuffer box 52. At the entrance to the stuffer box, the web is actedupon by a reverse folding means such as a pair of alternating,reciprocating bars 53, a star wheel folder (not shown) or the like. Theinitial plain web is thus transformed into a pleated or corrugatedstructure 54 which, as it passes through the stuffer box, is compacteduntil it emerges as a considerably bulkier web 55 which is highly suitedfor use as batting or padding in a great variety of products.Preferably, the discharge section 56 of stuffer box 52 is heated byheating means. The unbonded filamentary web 10 is thereby stabilized inits pleated form 55 by causing the filaments to set or to become fusedto one another at the points of intersection. When the Web is previouslypassed through a bonding agent applicator device 48 then heater section56 acts to stabilize the pleated web 55 in the same manner as the heaterdryer 49 shown in FIG. 2.

The final stabilized Web is thereafter taken up for storage orimmediately further processed as may be desired in the particular enduse. Again, it is to be noted that a plurality of individual spread towin either bonded or unbonded tow bands 10, can be cascaded or fedsimultaneously to stuffer box 52 at preselected relative speeds, inorder to facilitate the exercise of precise control over the base weightof alternate web 55.

In certain applications, it has been found desirable to apply thebonding agent only in a predetermined fraction or percentage of thetotal area of Web 10. Thus, the bonding agent can be applied in the formof a plurality of discrete dots or circular areas 57, as shown in FIG.5, arranged in a plurality of mutually perpendicular rows and columns.Various designs of application can be used including dots or areas inany given row or column being staggered with respect to the dots or areain the next adjacent row or column, with each two adjacent dots or areasof each preferably extending crosswise to the filament orientationoverlapping slightly the loci of the lateral boundaries of the dots orareas of the intermediate column extending lengthwise of the filamentorientation.

This spot bonding technique provides a novel continuous filamentfleece-like fabric possessed of excellent textile properties such assoftness or hand, flexibility or drape and three dimensional appearanceas noted in high loft characteristics. Because the bonding agent isapplied to only a predetermined fraction of the total area of theoriginal web 10, the fabric is rendered dimensionally stable while stillbeing fully flexible in all directions. High softness fleece fabrics ofthis type are particularly advantageous for the manufacture of a greatnumber of products such as surgical dressings, disposable table napkins,hand towels, diapers and the like, as well as numerous other products.

In addition to the method of increasing bulk illustrated by FIG. 4, thespread web 10 can be folded or lapped in accordance with FIG. 6 toincrease the thickness thereof. Folding or lapping device 63 is mountedfor reciprocal movements over endless conveying belt 64 on which the webis lapped. The reciprocating device 63 is reciprocated in a directionparallel to the direction of movement of the belt or at a directiontransverse tothe direction of the movement of the belt such as at anangle up to about degrees thereto. When reciprocating at an angle to thedirection of the belt, a cross lapped material is obtained. In eitherinstance, the speed of the reciprocation relative to the speed of theadvancement of the belt can be adjusted to increase or decrease thethickness or the amount of lapping produced. The reciprocating lappingof web and the movement of belt 64 coact to form a continuous mutli-plyweb structure 66. It will be noted that if reciprocating device 63 movesparallel to belt 64, the filaments in each ply are all orientatedlengthwise of the web and thus linear to the direction of the advance ofthe web, whereas if reciprocating device 63 moves transversely to thebelt, the filaments in each ply are orientated angularly to thedirection of advance of the web and, of course, angular relative to thefilaments in the next adjacent pile. The number of piles per unit lengthof web 66 and the angle of cross lapping is determined by the relativespeeds of the belt, the feed rates of web 10 to reciprocating device 63,the reciprocating rate and the angle of traverse, if any, to thedirection of movement of belt 64.

The multi-ply web structure 66, whether of the linear lapped or crosslapped type, produced by the method of FIG. 6, is bonded or otherwisesubject to further treatments to dimensionally stabilize it as hereindescribed, for use in the manufacture of particular end products. Thus,multi-ply web 66 may be taken up in a suitable form, such as a roll, orsent directly for further processing. Such further processing includesthe formation of the lapped product into items such as battings orstufiings for pillows, comforters, cushions, upholstery, insulatingpadding and the like. In the formation of materials such as comforters,sleeping bags, cushioning materials and the like, the various processingtechniques described in FIGS. 7, 8, 9 and 10 are preferably used toachieve the greater degree of dimensional stability desired. Asdescribed hereinbefore, the lapped material can be bonded in its entireyor spot bonded as may be desired.

For use in products wherein a bonding agent is deemed to be undesirableor incapable of imparting the ultimate physical characteristics to theend product, the web of the present invention, whether lapped orunlapped, may be fed into and through a stitching device as illustratedin FIGS. 8 and 9. Stitching device 68 can be operated on the web alonewithout an additional sheet material, or as is often desired forcushioning materials such as comforters, insulating clothing, sleepingbags and the like, in conjunction with a dimensionally stable sheetmaterial such as a knitted, woven or nonwoven fabric. The sheet materialis applied to either or both sides of the web. The web is thus stitchedeither crosswise, at regular intervals, in singular or multiple zigzagpatterns or quliting as indicated at 70 in FIG. 8.

The operation is preferably effected by feeding the web into thestitching device by first passing the web through a slack absorbingmechanism shown diagrammatically in FIGS. 8 and 9 to apply a tensionalong the direction of the fibers. This is readily accomplished by anumber of methods such as the use of guide rollers 71, 72 and 73 whereinmiddle roller 72 is mounted for vertical displacement toward and awayfrom stationary rollers 71 and 73 as indicated by broken lines in FIG.9. In instances where the web material is cross lapped so that theorientation of the fibers is generally across the width, the tensioningis then preferably also applied across the width so as to exert atension along the length of the fibers. The tensioning is preferably inan amount insufficient to remove the crimp from the fibers butsufficient to stretch the fibers to their full length. Thispretensioning has been found to unexpectedly increase the loft orbulkiness to the end product. Such bulkiness increases the cushioningand insulating value of the final product.

As illustrated in FIGS. 7, 10, and ll, the spread web can bedimensionally stabilized in the form of a single ply or multi-ply web byattachment to one or more additional layers of sheet material. Asillustrated in FIG. 7, a

single or multi-ply spread web 10 is dimensionally stabilized by feedingit toward a pair of calender rolls 74 and 75 to which is simultaneouslyfed another sheet material 76 taken from a supply roll 77. In the methodspecifically illustrated, sheet material 76 is first passed over a guide78 and hence to an applicator roll system 79 where a suitable bondingagent is applied to at least the surface of sheet material 76 to becontacted by web 10. The sheet material is then passed through calender74 and 75 with web 10. Sheet material 76 may be any of numerousmaterials, particularly fibrous materials such as woven scrim fabric,knitted fabric such as tricot fabric, staple fiber, nonwoven battingsuch as a needle punched nonwoven, or nonfibrous backing material suchas sponge rubber, plastic sheeting and the like as well as paper andleather. Web 10 may have been stabilized as hereinbefore described suchas by bonding, stitching or the like or in the unstabilized form as itis produced. In the same manner, rather than bonding with an adhesivematerial, the laminate can be produced by stitching as hereinbeforedescribed.

The combined spread web and sheet material, upon curing of the bindingagent, results in a unitary laminate structure 80 which can be taken upfor storage or immediately further processed into end products such asgarments, drapery fabrics, and the like. It will be further understoodthat sheet material 76 may be, rather than the aforementioned sheetmaterials such as a woven, knitted or staple-fiber, nonwoven fabric, aweb of opened and spread tow similar to web 10. Thus, either or both ofthe webs may be a single-ply structure, either or both of the webs maybe linearly or cross-lapped and either or both of the webs may have beenpreviously stabilized by prior bonding, needling or stitching orlaminating operations. Especially where both webs are of the same type,such as both are linear lapped or single ply, it is preferred, inaccordance with still another aspect of this invention, to laminate themwith the filament orientations or adjacent web sections transversed toeach other to form right angles to one another. To accomplish this,therespective spread tow or web is cut or otherwise formed in the desiredfilament direction such as by cross lapping one web onto another Web.

As previously indicated, the laminating operation may involve more thanone web or sheet material. This is more specifically illustrated in FIG.10 wherein 3 webs, X, Y, and Z or a combination of webs and sheetmaterials are sandwiched together. 'Ihus, X, Y, and Z may all besingleply, opened and spread tow bands 10 which, prior to lamination arefed through respective layering devices 81, 82, and 83. For example,devices 81 and 83 may produce linearly lapped webs while device 82produces a cross lapped web, or vice versa. Additionally, X and Z can besheet material such as knitted, woven or nonwoven fabric and Y can be aspread web, cross lapped web, linearly lapped web or the like. Theresulting combination of X, Y, and Z is then fed to a pair of calenderrolls 84 and 85 with or without the application of a bonding agent toadhere the laminates. Or, as more specifically illustrated, stitchingdevice 86 is used to bind the sandwiched materials together in themanner illustrated in FIGS. 8 and 9. 1

In another aspect of the foregoing laminating process, a laminatestructure is formed with a pleated web 55 of the type produced inaccordance with FIG. 4. This aspect is more specifically illustrated. inFIG. 11 wherein bonded or unbonded spread tow band 10 is fed by means offeed rollers or the like through folding means 53 and into stutter box52. Simultaneously therewith, two bands of sheet material 76 are fedinto the stuffer box on the opposite sides of loosely pleated web 54.Again, sheet materials 76 may be scrim fabrics or any of the previouslydescribed materials such as those described for FIG. 7.

As web 54 advances through the narrowing funnel intake of stufiFer box52 into heater section 56, it is compacted to form web 55. At the sametime, the bands of sheet material 76 are pressed into intimate contactwith the opposite faces of web 55. To achieve adhesion of sheet material76 to web 55, web is first passed through a bonding agent applicatordevice 48 and/ or bands of sheet material 76 are passed throughrespective bonding agent applicator systems 79 Or the like. Theresulting composite fabric structure, which is illustrated in FIG. 12 inan enlarged partial sectional view wherein the vertical lines representthe spread web, is then ready to be taken up by any suitable take upmeans for storage or further processing into end use items. Thisproduced fabric is particularly useful for upholstery coverings,insulating wear, sleeping bags, mattress pads, and the like cushioningand insulating materials. It will be readily recognized, that thedensity of the fibrous fabric produced by the method illustrated in FIG.11, can be readily controlled by controlling the feed rates of thevarious components such as the sheet material 76. Thus, a wide varietyof fabric textures can be readily produced by this method.

The invention will be described more fully by reference to the followingexamples which illustrate certain preferred embodiments of the presentinvention.

EXAMPLE 1 A polyester continuous filament tow having a total denier of220,000, a denier per filament of 5.0 and about 8 crimps per inch wasprocessed through a tow opening and crimp deregistering apparatus of thethreaded roll type disclosed in the hereinbefore mentioned Dunlap etal.patent, said apparatus having a first pair of rolls operating at a speedof about 21.3 yards per minute, and a second pair of rolls operating ata speed of about 30 yards per minute. The resulting opened tow was inthe form of a band about 12 inches wide. Thereafter, the opened tow waspassed under a tension of approximately 8 ounces over a spreading deviceconsisting of 2 curved bars. The spread tow band was approximately 40inches wide and had a base weight of about 0.8 ounce per square yard.The web so formed was fed to a laying device and there formed into amulti-ply cross lapped structure. The latter is then dimensionallystabilized by laminating to a woven scrim fabric in accordance with FIG.7, using about 20 weight percent butadiene urea formaldehyde emulsionsolids pickup. The resulting product is particularly useful forfurniture batting and other cushioning material.

EXAMPLE 2 The same type polyester tow of Example 1 was againderegistered in accordance with FIG. 1 using the operating speeds ofExample 1. The tow was then spread from a band of about 12 inches to awidth of about 60 inches by passing the tow through two air spreaders.The spread web weighed about 0.5 ounce per square yard. The web is thencross lapped in accordance with FIG. 6 to a thickness of 7 to 10 websand dimensionally stabilized by applying an acrylic emulsion bondingagent to the filament and calendering. The resulting batting isparticularly suited for use as carpet backing and carpet underlay pads.

EXAMPLE 3 A polyester continuous filament tow having a total denier of225,000 and a denier per filament of 5.0 was processed on the threadedroll tow opening device as in Examples 1 and 2 and thereafter spread toform a band having a width of approximately 28 inches and a base weightof about 1 ounce per square yard prior to being linearly lapped. Sixteenweb segments of this band were then plied together, as follows: fourwebs with filaments oriented in one direction; atop these, eight webswith their filaments arranged crosswise to the filaments 0f the lowerWebs; atop these, four webs with their filaments parallel to those ofthe bottom webs. This structure is then stitched in a quilted patternthereby dimensionally stabilizing the nonwoven material the resultingproduct is extremely bulky, soft, and resilient. It is particularlyuseful for cushioning material such as furniture batting, carpetunderlay padding and insulating material. In addition to the greatesttensile strength of this product compared to staple fiber batting, agreater force is required to remove tufts of fiber, as evidenced by thelower tendency of the tow batt to fuzz up under abrasion. Moreover, thetow batt is found to be completely free of the problem of fibermigration and to have superior launderability properties, which greatlyenhances its suitability for use as a fabric in the manufacture ofblankets, clothing, etc.

In the same manner, when the end use is for items such as mattress pads,insulating clothing, and the like, a woven knitted or needle-punched orbonded nonwoven is applied to one or both sides of the web materialprior to stitching.

EXAMPLE 4 A 1.6 denier per filament, 40,000 total denier dull acetatecontinuous filament tow was processed on the threaded roll tow openingapparatus of the Dunlap et a1. patent in which the first set of rollswere operated at a speed of about feet per minute, and the second set ofrolls at about 220 feet per minute. The opened tow band, which was about4 inches wide, was then spread to a width of 12 inches. The web soformed was found to have a base weight of 0.53 ounce per square yard. Aportion of this web was passed at a speed of 150 feet per minute througha chamber containing triacetin mist as a bonding agent in accordancewith FIG. 2. The ultimate bonded web was found to have a base weight of0.55 ounce per square yard and to be of increased dimensional stability.This product was particularly suited for further processing asillusrated in FIGS. 4, 6, 7, 8, 10, and 11.

EXAMPLE 5 A second portion of the spread tow web of Example 4 was bondedin the same manner but additionally was calendered at a temperature of225 F. and no pressure other than the contact pressure of the calenderrolls. The bonded web was found to have a base weight of 0.55 ounce persquare yard. The tow processed as in accordance with this and thepreceding example, is advantageously used as backing material, patternmaterial, industrial carrier webs, sanitary napkin covers, seed bedmaterial, filtration fabrics, reinforcing material for plasticlaminates, etc.

EXAMPLE 6 A polyester continuous filament tow having a total denier of225,000 and a denier per filament of 5.0 was opened and spread into aband 40 inches wide in accordance with FIG. 1 as set forth in thepreceding examples, with the first pair of rolls of the tow openingapparatus operated at a speed of about 12 yards per minute, and thesecond pair of rolls at a speed of about 21.4 yards per minute. Thespread web was then cross lapped into a batting having a base weight of9.6 ounces per square yard and a width of 27 inches. The batting wasinterposed between two sheets of cotton scrim, and thereafter both sidesof the sandwich structure were sprayed with a bonding agent composed ofa water dispersion containing 55 percent by weight of modified vinylchloride polymer and 1 part water. Finally the entire laminatedstructure was dried by being passed twice at a speed of 8 feet perminute through an infra-red oven set at 320 degrees Fahrenheit. Thefinished fabric had a base weight of 21.1 ounces per square yard and aheight of 2 inches at zero compression, and was found to be free offiber migration and to compare favorably with a corresponding staplefiber sandwich in the properties of compressibility, recovery, retentionof bulk, etc. This product is particularly suited for use in themanufacture of upholstery stuffing, furnace and air conditioner airfilters, sleeping bag insulation, blanket interliners, etc.

EXAMPLE 7 An opened and spread polyester continuous filament tow havinga total denier of 220,000 and a denier per filament of 5.0 was processedinto a linearly lapped web 36 inches wide. Opening was accomplished bymeans of the threaded roll apparatus as described in Example 1. Threeportions of this web were plied with the filaments of the middle weboriented transversely to the filaments of the outer webs. This assembly,having a base weight of 2.7 ounces per square yard, was then sandwichedbetween two plies of woven nylon fabric. The sandwiched layers were thensecured by sewing a quilted pattern of 2 inch square quilts across thenylon fabric while applying a tension to the fibers along theirlongitudinal direction. The tension applied was sufiicient to stretchthe fibers but insufficient to permanently remove the crimp. Afterquilting, the tension was released. The finished structure was possessedof a high loft, excellent washability and insulating qualities and wasfound to be suitable for use in such products as insulated garments,comforters, quilts, bedspreads, etc. The product was free of fibermigration, as well as being highly resistant to the removal of tufts offibers vis-a-vis a corresponding staple fiber structure.

EXAMPLE 8 A cellulose acetate continuous filament tow having a totaldenier of 50,000 and a denier per filament of 3.2 was processed by thethreaded roll apparatus into an opened and spread band or web 12 incheswide in the manner hereinbefore set forth. Two portions of the resultingweb were plied together with the filaments in each ply orientedtransversely to the filaments in the other ply. The assembly was thenpassed through a spot bonding apparatus which applied to the filamentarystructure discrete and overlapping circular areas of triacetin, inaccordance with that illustrated in FIG. 5, covering approximately 25percent of the total surface area of the fabric structure. The bondedfabric was found to have good strength properties both lengthwise andwidthwise and was adapted for use in the production of interliners,surgical dressings, hand towels and diapers. In comparison withheretofore known spot bonded staple fiber nonwoven fabrics, the spotbonded continuous filament nonwoven fabric was found to be free of fibermigration and also to compare favorably with the staple fiber fabrics insuch textile properties as softness, flexibility, drape and loft.

While there have been described various embodiments of the presentinvention, the method described is not intended to be understood aslimiting the scope of the invention as it is realized that changestherein are possible.

What is claimed is:

1. A process for producing a nonwoven continuous filament productcomprising the steps of longitudinally advancing a crimped continuousfilament tow, subjecting said tow while said tow is in motion to adifferential gripping action at a plurality of points spaced from oneanother transversely of said tow and defined by at least one pair ofopposed surfaces one of which is profiled and the other of which issmooth, to effect a deregistration of the crimps of said tow, spreadingthe deregistered tow to a weight of less than one ounce per square yardto produce a web and subsequently dimensionally stabilizing the web toproduce a nonwowen continuous filament product.

2. The process of claim 1 wherein the web is dimensionally stabliized byapplying a bonding agent to the fibers thereby bonding the web.

3. The process of claim 2 wherein the web is pleated.

4. The process of claim 1 wherein the web is dimen- 12 sionallystabilized by attaching the web to a sheet material.

5. The process of claim 4 wherein the web is attached to a sheetmaterial by stitching.

6. The process of claim 4 wherein the web is laminated between at leasttwo fibrous sheet materials.

7. The process of claim 4 wherein the web is stabilized by placing theweb between at least two sheet materials placing a tension on the web inthe filament direction, stitching the web and sheet material together,and subsequently releasing the applied tension.

8. The process of claim 4 wherein the web is linearly lapped prior toattaching to said sheet material.

9. The process of claim 4 wherein the web is crosslapped prior toattaching to said sheet material.

10. The process of claim 4 wherein the web is attached to the sheetmaterial by applying a bonding agent to at least one of said web andsheet material and subsequently pressing said materials together.

11. The process of claim 10 wherein the web is pleated.

12. The process of claim 10 wherein the web is pleated, compressed andbonded between two fibrous sheet materials.

13. The process of claim 1 wherein the tow is comprised of polyethyleneterephthalate filaments.

14. The process of claim 1 wherein the tow is comprised of celluloseacetate filaments.

15. The process of claim 1 wherein the deregistered tow is spread to aweight of less than about 1 ounce per square yard, said web beingstabilized by lapping the web to produce a multi-ply web, placing theweb between at least two fibrous sheet materials, placing a tension onthe web in the filament direction, stitching the web and sheet materialtogether and subsequently releasing the applied tension. I

16. A continuous filament product comprising a crimped deregisteredspread web of continuous filaments, wherein said web comprisescontinuous filament tow having the crimps of said tow deregistered bythe difi'erential gripping action of at least one pair of opposedsurfaces one of which is profiled and the other of which is smooth andsaid web is initially spread to a weight less than about one ounce persquare yard, said web being dimensionally stabilized by the applicationof supporting means at least transversely to the primary orientation ofthe continuous filaments.

17. The product of claim 16 wherein the web is crosslapped to a weightmore than the original spread weight.

18. The product of claim 16 wherein the web is linearly lapped to aweight more than the original spread weight.

19. The product of claim 16 wherein the supporting means of said web isa sheet material attached to said web.

20. The product of claim 19 wherein the sheet material is a fibrousmaterial.

21. The product of claim 19 wherein the web is attached to the sheetmaterial by stitching.

22. The product of claim 19 wherein a multiple of said webs are attachedby stitching between at least two fibrous sheet materials.

23. The product of claim 19 wherein the web is bonded with a bondingagent to said fibrous sheet material.

24. The product of claim 23 wherein the web is pleated and bondedbetween at least two fibrous sheet materials.

25. The product of claim 16 wherein the web is comprised of polyethyleneterephthalate filaments.

26. The product of claim 16 wherein the web is comprised of celluloseacetate filaments.

27. The product of claim 16 wherein the supporting means of said web isspot bonding.

28. A quilted article comprising a crimped deregistered spread web ofcontinuous filaments sandwiched between at least two fabric sheetmaterials, wherein said spread web comprises continuous filament towhaving the crimps of said tow deregistered by the differential grippingaction 13 of at least one pair of opposed surfaces, at least one ofwhich is profiled, and said web is initially spread to a weight lessthan about one ounce per square yard, said Web being dimensionallystabilized by the application of at least one of said fabric sheetmaterials transversely t0 5 References Cited UNITED STATES PATENTS4/1957 Smith 28-72 X 1/1962 Smith 19-65 14 3,071,783 1/1963 Gamble 5-3373,235,935 2/ 1966 Daruwalla 28-722 FOREIGN PATENTS 1,258,476 3/1961France.

ROBERT F. BURNETT, Primary Examiner R. L. MAY, Assistant Examiner U.S.Cl. X.R.

